How to snap object back to its original position
Resetting all Transform values to 0 is Alt+G for location, Alt+R for rotation and resetting scale to 1 is Alt+S. After performing these three steps Transform location will be (0, 0, 0), rotation (0, 0, 0) and scale (1, 1, 1).
To set it back to a different location/rotation/scale, these differing values should be set in the Delta Transform properties of the object. Delta or Δ stands for (among other things) &quot;difference&quot; in mathematics and means in this case the divergence from the &quot;normal&quot; Transform properties.
Looking at this cube, it has a Transform location and a Delta Transform location. They have to be added together to get the actual world location of the cube (or multiplied for scale):

In case your object has Delta Transforms, then resetting the Transform values will result in (0, 0, 0) + Δ(x, y, z). So this way your object resets to a location different from the world origin.
Now, moving an object by hitting G only changes the Transform location, not the Delta Transform. If you moved an object to a location which should be its new &quot;original&quot; location, then you can apply these transforms with Ctrl+A &gt; Apply &gt; All Transforms to Deltas. In the options you can then also choose if you want to apply all transforms or just Location, Rotation or Scale and if you want to reset the normal transforms.
After doing it you can see that now the Transform location of the cube is reset to (0, 0, 0) while the new Delta Transform location is (7, 2, 1). This is its new &quot;original&quot; location. When you move the cube with G, resetting the transform with Alt+G moves it back to (7, 2, 1).